UC San Diego

43 Pages·2014·0.63 MB·English

UC San Diego
UC San Diego Electronic Theses and Dissertations
Title
Glucocorticoid mediated regulation of inflammation in human monocytes is associated with
obesity and depressive mood /
Permalink
https://escholarship.org/uc/item/2ts333d9
Author
Cheng, Tiefu
Publication Date
2014

Peer reviewed|Thesis/dissertation
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University of California
UNIVERSITY OF CALIFORNIA, SAN DIEGO

Glucocorticoid mediated regulation of inflammation in human monocytes is
associated with obesity and depressive mood

A Thesis submitted in partial satisfaction of the requirements for the degree
Master of Science

in

Biology

by

Tiefu Cheng

Committee in charge:

Suzi Hong, Chair
Kathleen A. French, Co-Chair
P. A. George Fortes

2014
Copyright
Tiefu Cheng, 2014
All rights reserved.
The Thesis of Tiefu Cheng is approved and it is accepted in quality and form for
publication on microfilm and electronically:

________________________________________________________________________

_____________________________________________________________
Co-Chair

_____________________________________________________________
Chair

University of California, San Diego
2014

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TABLE OF CONTENTS
Signature Page………………………………………………………………………… iii
Table of Contents……………………………………………………………………... iv
List of Figures…………………………………………………………………………. v
List of Tables………………………………………………………………………….. vi
Acknowledgements…………………………………………………………………… vii
Abstract……………………………………………………………………………….. viii

Introduction…………………………………………………………………………... 1
Materials and Methods……………………………………………………………….. 7
Results………………………………………………………………………………… 13
Discussion……………………………………………………………………………... 17
Figures and Tables…………………………………………………………………….. 23
References…………………………………………………………………………….. 29

iv
LIST OF FIGURES
Figure 1: Example flow cytometry outputs measuring % TNF+ monocytes from human
blood after ex vivo stimulation with LPS…………………………………………….. 24
Figure 2.1: Human monocyte LSP-stimulated TNF production from ex vivo treatment
with three doses of cortisol……………………………….…………………………... 25
Figure 2.2: Inhibition of human monocyte TNF production by ex vivo cortisol……. 26
Figure 3: Human monocyte LPS-stimulated TNF production from ex vivo treatment with
three doses of cortisol and glucocorticoid and mineralocorticoid receptor
antagonists.…………………………………………………………………………… 28

v
LIST OF TABLES
Table 1: Demographic characteristics………………………………………………... 23
Table 2: Multiple regression results………………………………………………….. 27

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ACKNOWLEDGEMENTS
I would like to thank Dr. Suzi Hong for her tireless guidance and support for all
my endeavors in the laboratory. Her commitment to my success and education has taught
me the meaning of mentorship. I am also grateful for the teachings of Dr. Stoyan
Dimitrov and all members of the Hong Lab and others in the Psychiatry department who
made my work possible.
I am also thankful for Dr. Kathy French and Dr. George Fortes for being members
of my committee.

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ABSTRACT OF THE THESIS

Glucocorticoid mediated regulation of inflammation in human monocytes is associated
with obesity and depressive mood
by
Tiefu Cheng

Master of Science in Biology
University of California, San Diego, 2014
Suzi Hong, Chair
Kathleen A. French, Co-Chair

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is most
significantly studied via glucocorticoid (GC) receptor desensitization and has been
associated with depression, inflammation, and also obesity, while various bidirectional
links seem to exist also between these variables. To understand better and characterize
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the relationship between GC desensitization and these health variables, we recruited 36
average health participants and assayed their obesity via body mass index (BMI),
depressive mood via Beck Depression Inventory (BDI-Ia), plasma cortisol via ELISA,
and LPS stimulated monocyte TNF production via whole blood incubation with receptor
agonists and antagonists for GC. Cortisol sensitivity was characterized as change in
percent monocyte TNF production from baseline to inhibited conditions. The main
findings were that % TNF+ monocytes without cortisol correlated with depressive mood
(BDI-S: r= -0.336, p= 0.045), as did depressive mood with cortisol sensitivity after
controlling for population demographics (BDI-S: β= -0.289, p= 0.013). BMI also
independently correlated with cortisol sensitivity (BMI: β= -0.273, p= 0.020). With
demographics, BMI, BDI-S, % TNF+ monocytes without cortisol in the final multiple
regression model, only BDI-S (β= -0.215, p= 0.074) and % TNF+ monocytes (β= 0.546,
p= 0.000) still predicted cortisol sensitivity. Secondary findings with antagonists saw that
relative blocking effect of mifepristone increases with increasing concentration of cortisol
inhibition, while not with spironolactone. Our results find a strong relationship between
the triad of HPA dysregulation, depression, and obesity through the inflammatory
potential of monocytes. This preclinical sample reinforces significance of the
pathophysiological triad, though require further mechanistic exploration.

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